甜瓜黑点根腐病菌生物学特性及其对药剂敏感性测定

Biological characteristics of Monosporascus cannonballus and its sensitivity to fungicides

为明确甜瓜黑点根腐病的发生和流行规律及有效防治方法,在不同培养基、碳源、氮源、温度、pH等培养条件下,测定甜瓜黑点根腐病菌的生物学特性及其对多种瓜类作物致病性,并采用菌丝生长速率法测定菌株对不同药剂的敏感性。结果表明,甜瓜黑点根腐病菌MC8菌丝生长的适宜培养基为马铃薯蔗糖培养基、燕麦粉琼脂和马铃薯葡萄糖琼脂培养基,马铃薯蔗糖培养基、燕麦粉琼脂和玉米琼脂粉这3种培养基可产生子囊壳;碳源和氮源对菌丝生长无明显促进作用,但乳糖可显著促进子囊壳产生,该发现为国内外首次报道;MC8菌丝生长的适宜pH为5~7,菌丝和子囊壳生长最适温度为30℃。致病力试验结果显示MC8菌株可侵染西瓜、甜瓜、南瓜和葫芦多种瓜类作物。咪酰胺和嘧菌酯在PDA上对瓜类黑点根腐病菌的菌丝生长有较好的抑制效果。

To clarify the occurrence and epidemics of Monosporascus spot root rot and its effective control,biological characteristics of the fungal pathogen M.cannonballus were studied under different media,carbon and nitrogen sources,temperatures and pH values,and their susceptibility to fungicides were determined by using the mycelial growth rate method.The results showed that the suitable medium for mycelial growth of MC8 was potato sucrose medium,oat meal agar and potato dextrose agar,and the perithecia could be produced on potato sucrose medium,oat meal agar and corn meal medium.Carbon and nitrogen sources did not significantly promote the mycelial growth of MC8,but lactose could significantly promote the production of perithecia,which was first reported worldwide.The optimum range of pH value for mycelium growth was 5~7.The optimum temperature for mycelium growth and perithecia production of M.cannonballus was 30℃.The pathogenicity test showed that MC8 could infect watermelon,melon,pumpkin and gourd.The fungicide sensitivity test showed that prochloraz and azoxystrobin had the best inhibitory effect on the mycelial growth of M.cannonballus strain MC8 on PDA.